The invention concerns an intake device of an internal combustion engine, in particular of a motor vehicle, with a primary intake line and a secondary intake line for aspirating combustion air.
DE 10 2006 016 433 A1 discloses an intake device for an internal combustion engine of a motor vehicle with a primary intake line and a secondary intake line. An intake port of the primary intake line for aspirating external air is located at the exterior of the motor vehicle. An intake port of the secondary intake line is arranged in the engine compartment. A switch valve is provided for switching between the primary intake line and the secondary intake line. In order to prevent water from entering through the primary intake line, the switch valve is actuated when driving off-road. Either the primary intake line or the secondary intake line is thus opened in order to aspirate combustion air. In particular in winter or in cold regions, it may happen that even during normal operation of the motor vehicle on roads, i.e., not during off-road operation, the primary intake line may become closed off (clogged), in particular by snow or ice. This cannot be detected by the intake device of the prior art, and the internal combustion is then no longer supplied with sufficient combustion air through the primary intake line in order to ensure operation of the internal combustion engine. The engine “dies”.
The invention has therefore the object to design an intake device of the aforementioned kind in such a way that operation of the internal combustion engine is ensured in a simple and reliable way even upon closure (clogging) of the primary intake line.